Well now, This is interesting! 4-1 saying they're getting better. 
First of all, let me say I'm the one vote (currently) for "decrease". I will admit that the later sequels have been generally more *entertaining* (more action, prettier effects, fewer dull moments) but there seems to be generally less care in handling dialog and character behaviour and less focus on what was the essense of the LBT sequels (mainly in 2-4). It's difficult to pinpoint but I just don't feel the same things toward the later sequels as I do for the earlier ones. I won't usually say to myself "Do I want to watch LBT 2 or LBT 8?" Instead I'll say to myself "Do I want to watch an old LBT (1-4) or a new LBT (5-12)?" then I'll break it down from there.
To keep this relatively short (I've mentioned a few points comparing the sequels in other threads such as this one...), I think the sequels are in such different eras that comparing them is like comparing apples to oranges. LBT 2-4 and 5-12 (currently) were developed using completely different styles. I just feel that LBT 2-4 felt more genuinely true to the LBT I felt had developed throughout the series' progression. As of LBT 5, the rules began to change and LBT became not "LBT" but "NEW LBT". "LBT" as I knew and loved had disappeared. Enter "New LBT" with its own set of rules, which it seems to make up as it goes along (earlier sequels contradict later sequels and vice versa), and everything changes. A Good change? I think it's less structured and less organized, so No. That's the basics behind why I'm saying "decrease".
Don't get me wrong; I like the new ones. I just miss the old ones.
Well put!
Its no coincidence that 2-4 were directed by an entirely different director, Roy Allan Smith. He and the director of 5-12 worked on 5 together, and it shows, considering half the movie is dedicated to a lot of buildup and plot, and the ither being more focused on Chomper and wrapping up the loose ends quickly.
I get the sense that Roy Allan Smith was into making a lighter take on the original film, whereas Grovsner wanted to create an entirely new LBT world. And I think that's why he ended up getting to stay---he was better at making it kid-friendly.
Don't get me wrong, RAS isnt entirely perfect and CG isn't entirely bad. I look at 2, RAS's first, and 7, one of CG's first, a d they each feel like something the other would do. So they're not incapable of creating good or bad quality. They just have preferences.
